broke out systemd service definitions

modules/services/step-ca/mtls.nix

@@ -50,6 +50,16 @@ let
         type = lib.types.str;
         default = "5m";
       };
+      user = lib.mkOption {
+        description = "User account to run the mTLS renewal service as.";
+        type = lib.types.str;
+        default = "root";
+      };
+      group = lib.mkOption {
+        description = "Group to run the mTLS renewal service as. Defaults to the configured renewal user when null.";
+        type = lib.types.nullOr lib.types.str;
+        default = null;
+      };
       reloadUnits = lib.mkOption {
         description = "systemd units to try-reload-or-restart after a successful certificate renewal.";
         type = lib.types.listOf lib.types.str;
@@ -62,6 +72,85 @@ let
       };
     };
   };
+
+  mkMtlsRenewService = {
+    pkgs,
+    tlsCert,
+    tlsKey,
+    mtlsBundle,
+    reloadUnits ? [ ],
+    postCommands ? [ ],
+    user ? "root",
+    group ? null,
+  }:
+  let
+    serviceGroup = if group == null then user else group;
+    renewReloadScript = lib.concatMapStringsSep "\n" (unit: ''
+      if ${lib.getExe' pkgs.systemd "systemctl"} --quiet is-active "${unit}"; then
+        ${lib.getExe' pkgs.systemd "systemctl"} try-reload-or-restart "${unit}"
+      fi
+    '') reloadUnits;
+    renewPostCommands = lib.concatStringsSep "\n" postCommands;
+  in
+  {
+    description = "Renew the mTLS certificate when Smallstep marks it ready";
+    wantedBy = [ ];
+    after = [ "network-online.target" ];
+    wants = [ "network-online.target" ];
+    path = [ pkgs.coreutils pkgs.step-cli pkgs.systemd ];
+    serviceConfig = {
+      Type = "oneshot";
+      User = user;
+      Group = serviceGroup;
+    };
+    script = ''
+      set -euo pipefail
+
+      if ${lib.getExe pkgs.step-cli} certificate needs-renewal "${tlsCert}"; then
+        echo "Renewing mTLS certificate"
+      else
+        rc=$?
+        if [ "$rc" -eq 1 ]; then
+          echo "mTLS certificate does not need renewal"
+          exit 0
+        fi
+
+        if [ "$rc" -eq 2 ]; then
+          echo "mTLS certificate missing: ${tlsCert}" >&2
+          exit 1
+        fi
+
+        echo "step certificate needs-renewal failed with rc=$rc" >&2
+        exit "$rc"
+      fi
+
+      ${lib.getExe pkgs.step-cli} ca renew --force "${tlsCert}" "${tlsKey}"
+
+      umask 077
+      cat "${tlsCert}" "${tlsKey}" > "${mtlsBundle}"
+
+      ${renewReloadScript}
+      ${renewPostCommands}
+    '';
+  };
+
+  mkMtlsRenewTimer = {
+    onCalendar,
+    randomizedDelaySec,
+    unit ? "mtls-renew.service",
+  }: {
+    description = "Periodic Smallstep renewal for the mTLS certificate";
+    wantedBy = [ "timers.target" ];
+    timerConfig = {
+      Persistent = true;
+      OnCalendar = onCalendar;
+      AccuracySec = "1us";
+      RandomizedDelaySec = randomizedDelaySec;
+      Unit = unit;
+    };
+  };
+
+  
 in
 {
   flake.modules.nixos.mtls = { config, lib, pkgs, ... }:
@@ -73,12 +162,6 @@ in
     mtlsBundle = "${certDir}/${cfg.bundleFilename}";
     rootCA = "${certDir}/root_ca.crt";
     sanArgs = lib.concatMapStringsSep " " (san: "--san \"${san}\"") cfg.san;
-    renewReloadScript = lib.concatMapStringsSep "\n" (unit: ''
-      if ${lib.getExe' pkgs.systemd "systemctl"} --quiet is-active "${unit}"; then
-        ${lib.getExe' pkgs.systemd "systemctl"} try-reload-or-restart "${unit}"
-      fi
-    '') cfg.renew.reloadUnits;
-    renewPostCommands = lib.concatStringsSep "\n" cfg.renew.postCommands;
   in
   {
     options.mtls = opts;
@@ -102,59 +185,14 @@ in
         '')
       ];
 
-      systemd.services.mtls-renew = lib.mkIf cfg.renew.enable {
+      systemd.services.mtls-renew = lib.mkIf cfg.renew.enable (mkMtlsRenewService {
-        description = "Renew the mTLS certificate when Smallstep marks it ready";
+        inherit pkgs tlsCert tlsKey mtlsBundle;
-        wantedBy = [ ];
+        inherit (cfg.renew) reloadUnits postCommands user group;
-        after = [ "network-online.target" ];
+      });
-        wants = [ "network-online.target" ];
-        path = [ pkgs.coreutils pkgs.step-cli pkgs.systemd ];
-        serviceConfig = {
-          Type = "oneshot";
-          User = "root";
-          Group = "root";
-        };
-        script = ''
-          set -euo pipefail
 
-          if ${lib.getExe pkgs.step-cli} certificate needs-renewal "${tlsCert}"; then
+      systemd.timers.mtls-renew = lib.mkIf cfg.renew.enable (mkMtlsRenewTimer {
-            echo "Renewing mTLS certificate"
+        inherit (cfg.renew) onCalendar randomizedDelaySec;
-          else
+      });
-            rc=$?
-            if [ "$rc" -eq 1 ]; then
-              echo "mTLS certificate does not need renewal"
-              exit 0
-            fi
-
-            if [ "$rc" -eq 2 ]; then
-              echo "mTLS certificate missing: ${tlsCert}" >&2
-              exit 1
-            fi
-
-            echo "step certificate needs-renewal failed with rc=$rc" >&2
-            exit "$rc"
-          fi
-
-          ${lib.getExe pkgs.step-cli} ca renew --force "${tlsCert}" "${tlsKey}"
-
-          umask 077
-          cat "${tlsCert}" "${tlsKey}" > "${mtlsBundle}"
-
-          ${renewReloadScript}
-          ${renewPostCommands}
-        '';
-      };
-
-      systemd.timers.mtls-renew = lib.mkIf cfg.renew.enable {
-        description = "Periodic Smallstep renewal for the mTLS certificate";
-        wantedBy = [ "timers.target" ];
-        timerConfig = {
-          Persistent = true;
-          OnCalendar = cfg.renew.onCalendar;
-          AccuracySec = "1us";
-          RandomizedDelaySec = cfg.renew.randomizedDelaySec;
-          Unit = "mtls-renew.service";
-        };
-      };
     };
   };
 
@@ -178,7 +216,7 @@ in
     };
 
     config = {
-      home.packages = with pkgs; [
+      home.packages = with pkgs; lib.optionals cfg.enable [
         step-cli
         (writeShellScriptBin "mtls-generate" ''
           set -euo pipefail
@@ -195,6 +233,15 @@ in
           -enddate -in ${mtlsBundle}
         '')
       ];
+
+      # systemd.services.mtls-renew = lib.mkIf cfg.renew.enable (mkMtlsRenewService {
+      #   inherit pkgs tlsCert tlsKey mtlsBundle;
+      #   inherit (cfg.renew) reloadUnits postCommands group;
+      # });
+
+      # systemd.timers.mtls-renew = lib.mkIf cfg.renew.enable (mkMtlsRenewTimer {
+      #   inherit (cfg.renew) onCalendar randomizedDelaySec;
+      # });
     };
   };
 }